1. Field
Exemplary embodiments of the present invention relate to a semiconductor device, and more particularly, to a semiconductor device including air gaps and a method of fabricating the same.
2. Description of the Related Art
In general, a semiconductor device includes a second conductive structure formed between a plurality of first conductive structures, wherein an insulation layer is interposed between the second conductive structure and the first conductive structure. For example, the first conductive structures may include a gate, a bit line, a metal wire, etc., and the second conductive structures may include a contact plug, a storage node contact plug, a bit line contact plug, a via, etc.
As the degree of integration of semiconductor devices increased, an interval between the first conductive structure and the second conductive structure is gradually narrowed. For this reason, parasitic capacitance between the first conductive structure and the second conductive structure is increased. As the parasitic capacitance is increased, the operating speed of the semiconductor device is decreased and a refresh characteristic is deteriorated.
In order to reduce the parasitic capacitance, a method of lowering the dielectric constant of the insulation layer may be used. In semiconductor devices, an insulation layer is chiefly made of silicon oxide or silicon nitride. A silicon oxide layer has a dielectric constant of about 4, and a silicon nitride layer has a dielectric constant of about 7.
A reduction of parasitic capacitance is limited because a silicon oxide or a silicon nitride still has a high dielectric constant. A material having a relatively low dielectric constant has recently been developed, but the dielectric constant of the material may be not so low.